Q: Apple Magic Mouse is discoverable but will not pair to MacBook Pro

I am running OS X Yosemite ver 10.10.2. The Apple Magic Mouse is discoverable by my MacBook Pro but will not pair. That silly arrow chasing its tail just keeps on spinning with the words "connecting" but nothing is happening. Mouse batteries are good. All software updates are good as best I can tell. Bluetooth turned on and off many times. Deleted the bluetooth mouse out of the devices and reloaded.  Nothing seems to work.  Thanks.